Hello, first post on the forums. I'm trying to make certain units and/or buildings explode and deal splash damage around them when they are killed. I tried inserting attack-related commands in the death sequence of the said units, but it doesn't work. I assume this is because units being killed do not have a target to attack. Could you please help me?

Yes, you are partially correct. Voyager experiemented with this in an unreleased mod, and found that without a target, the attack actually spawns somewhere around 0x0 on the map. By giving the weapon a massive explosion radius, he was able to deal damage to everything on the map when Nuclear Silos were destroyed. However, when he calculated the radius he'd need to hit everything on the largest map size possible, his mod began to crash. As far as I know, he never isolated the problem and thus did not released his experiment.

To create a more localized damage effect on death, you'll have to deal in Plugins.